How it
worksHow to spot bad
ignition circuit -
In 1 minute
You ride along in your Acura or Honda when
suddenly your car cuts out. As you lose momentum
your car rolls a few feet to a stop . Friends and
strangers help push your car along. You've just
experience what most likley is an an ignition
fault. A simple block diagram shows you why your
car may have stopped. The battery takes it's path
from the ignition switch to the computer, igniter
and coil. (point mouse over
picture)

The next step is to check for sparks. Remove one end of the
plug wire. Insert a spark plug into the wire. Lay
the plug solid end to a suitable ground. E.g.
exposed bolt, nut, etc.

Warning:
Coil
shock may be hazardous due to abrupt body
movement causing injury. Practical step is to
isolate you from ground - Do not lean on metal
body panels, plastic bumpers okay. DO NOT
ATTEMPT on a distributerless ignition
system - with lethal voltages up to 70KV. Next
step is to check for spark at the coil. Connect
the plug boot on the right of the picture
directly to the output (secondary) of the coil
with a help of a wire to close the gap, if
needed. Make sure it closes.

My problem sounds like a main relay.Check
for fuel. Listen to the fuel pump. Listen to the
second click when ignition is first turn on. The
second click will coincide with the disappearing
"check engine light."

SO -YOU DO NOT HAVE SPARK

Could
it be something else. Open the oil cap to see if
the rocker arms are moving. If not, you will need
to deal with your tming belt first.

Educational lesson: An igniterrecieves square wave
signals ( in mA) sent from the ECU, determines
the rate of the signal and compares it to a
reference (the dwell time)which tells it how long
to charge the coil. When the signal goes to
ground the igniter cuts off power to the coil to
produce spark. In other words, it's an itegrated
time management circuit combined with a
transistor. On previous generation the reluctor
gives the signal to the igniter.

To
spot a bad igniter :

1. The
tachometer quits abruptly or jerks around before
stalling.2. No spark at
the coil. 3. No on/off voltage at the
coil's (+, - ) terminals when cranking.

Igniter

The distriutor
rotor spins inside the distributor delivering
spark to each plug wire in a timely manner.
Should it fail there will be no spark at the
plugs, however, you will see spark at the coil. Check for spark .To spot a bad rotor :

1. The
distributor is hot to the touch.2. No spark at
the plug wires.3. Spark is found at the coil. 4. A cricket noise is heard from
the distributor before stalling.

DistributorRotor

To
spot a bad ignition switch :

1. Car
stalls then retarts, then stalls after driving.2. Car runs fine
when key slightly held at start position.3. No battery + voltage at the
coil + positive terminal.

Ignition
Switch

To
spot a bad coil :

1. The
distributor was disturbed before it died.2. No spark at
the plug wires.3. No spark at the coil's output
(secondary.)

To
spot a bad ignition switch probe pins 3 with the
top LED jig and pin 2 with the bottom BULB jig: Warning: DO NOT BE CONFUSED.
Probing pin three with the bulb jig (bottom jig)
may harm the coponent in circuit. The igniter may
be designed for 100 mA max or
input voltages of -0.3 to + 0.3. The LED jig has a low
impedance. Use the LED jig for all circuit tests
before investigating further.

Step 1.
Clip the positve end of the LED probe to the
battery positve terminal.Step 2. Clip the
LED probe pin 3. Crank the engine (assuming no
spark) at the plug wires.Step 3. Do you see blinking? No-
ECU is bad, check for ECU codes. Yes-Coil/igniter
is bad go to step 4.Step 4. Connect the BULB probe
tip to - negative terminal of the coil, it may be
labled [-].Step 5. Do you see blinking? No
- Igniter bad, replace it. Yes - Coil bad replace
it. Coil spark checked.

Terminals colors
for 90-93 Accords

1. Blue
for most Hondas/Acuras.2. Blu2, Blu1 is
for tach with in series resistor.3. Blk/Yel.4. Yelow green (Do not test with
a test lamp.)

Terminals colors
for 86-89 Accords if applicable.

1. Blue.2. Lt/Grn but, at
coil end Blk/Wht.3. Blk/Yel.4. Not used. The reluctor is
tied directly to igniter.